Available in the market over the years have been hinges for furniture comprising an arm adapted to be fixed to a fixed element of the furniture, and a box-shaped element adapted to be fixed to a door of the furniture, a first and a second equaliser connecting the box-shaped body and the arm operatively to each other and they define an articulated quadrilateral therewith.
Such hinges usually have springs of various types for creating a closure and/or opening restoring force of the doors on which they are applied. In such hinges, the presence of devices for decelerating the movement of the doors caused by the elastic reaction of such springs is desirable. First and foremost, such deceleration devices have the object of preventing noises due to violent impacts against the body of the furniture when closing the door.
Known are deceleration devices based on the use of viscous media interposed between the parts in mutual movement.
Such devices reveal a serious drawback linked to the fact that the efficiency of the deceleration device strongly depends on the ambient temperature in which the viscous medium operates being that its viscosity clearly depends on such temperature.
For example, use of a medium with a high viscosity might be counterproductive if the ambient temperature drops excessively given that it might cause the hinge to block, while the use of a medium with a low viscosity might be inefficient if the ambient temperature rises excessively (for example if a light beam produced by an artificial light present in a room is directed the hinge in question).
Provided for have been deceleration systems having a combined effect of the mechanical/viscous type for decelerating the rotation of the hinge.
In particular, reference is made to deceleration systems in which a plastic container filled with a viscous fluid accommodates a friction disc actuatable in rotation against a friction surface. In particular, a slider translatable due to the rotation of the hinge supports a drawing element adapted to transform the translation of the slider into a rotation of the friction disc.
Such deceleration systems reveal the drawback of having a limited structural efficiency and resistance alongside a short duration linked to the high stress and wear the parts they are made up of are subjected to.
In particular, in some of such systems, the slider is required to simultaneously have characteristics in conflict with each other, i.e. sufficient rigidity to rotate the friction disk during the hinge closure rotation and sufficient elasticity in a manner such to be capable of bending during the hinge opening rotation so as not to move the friction disc. The repeated mechanical stress on the slider may lead to its breakage, especially taking into account the fact that when the hinge remains idle for a long period of time, the static molecular adherence of the viscous fluid is greater and thus increases the force required for the subsequent rotational actuation of the hinge and hence also the mechanical stress the slider is bound to bear.
Furthermore, it should be added that in such deceleration systems the forces to which the slider is subjected to are often concentrated at only one of its zones which inevitably weakens gradually.
Another drawback observed on a traditional deceleration system applied outside the box-shaped body of the hinge is linked to the necessity of having an ideal rigidity and mechanical resistance so as to maintain an intact configuration even in case of possible mechanical stresses required during its installation, such as for example stresses occurring if the hole of the door of the furniture is not accurately dimensioned to accommodate the box of the hinge it is required to receive. In such case, a deformation of the container of the deceleration system may lead to deteriorating the performance of the device, greater wear of the parts and hence a short duration as well as extra maintenance costs.